In shipping various types of products in railroad freight cars on large pallets, in large containers, or the like, it has been necessary in effect to divide the car into temporary compartments in order to limit shifting of the lading and to reduce the load imposed on the ends of the car. For example, in a car loaded with relatively heavy mechanical parts, shifting of the entire load due to rapid stopping or starting of the car might impose a sufficient load on an end of the car to push it out or at least to bulge it substantially.
It has been the practice to ship various parts such as automobile parts, stampings and the like, as well as various subassemblies such as fenders, doors, and other body and frame parts, on pallets that extend the full width of a car and may be stacked vertically to fill substantially the full height of the car. Cars of this type are normally separated into three or more temporary compartments by bulkheads or lading separators that can be moved to different positions longitudinally of the car where they may be locked in place. These bulkheads engage the pallets and the materials thereon to limit shifting thereof in the car during transport.
Movable lading separators or freight bracing bulkheads for use in railroad freight cars in the manner just described have been known for many years. They have generally been supported by a carriage assembly of a type that extends across the car and is designed to travel along tracks in the upper portions of the freight car on both sides of the same, with the separators or bulkheads suspended from their two upper corners so they can be moved to different positions lengthwise of the car, where they separate the lading and hold it securely against displacement.
The movable bulkheads or separators most widely used in the prior art have extended completely across the width of the freight transporting vehicle. Some of these devices have provided bracing for the freight or lading that substantially completely encloses the space in which the freight or lading is located. Others of these devices, such as the device disclosed in U.S. Pat. No. 3,168,055 issued Feb. 2, 1965 to Vander Hyde et al., have had an open frame construction.
Some types of lading do not require lading separators or bracing devices that extend completely across the width of the transporting vehicle. Typical of such loads are large cartons containing automobile parts or subassemblies such as mentioned above, large appliances, or the like. In such cases, the necessary bracing can be accomplished merely by restraining the outer edge portions of the load, as for example by a pair of relatively narrow, elongated stanchions or columns that are suspended from tracks such as those used with the full width movable bulkheads, one of the stanchions being suspended from the track on each side of the vehicle. The cargo restraining surface of any such stanchion or column of course extends transversely for substantially less than one-half of the width of the cargo area in the transporting vehicle.
Movable freight restraining devices of the stanchion type just mentioned, such as the device disclosed in U.S. Pat. No. 4,208,970, have the advantage of substantially reducing the weight of the bracing device, while still providing a permanent installation in the transporting vehicle. However, when the suspended stanchion is at rest with its bottom end unrestrained, because of the construction of the carriage means from which the movable stanchion is supported in prior art devices such as that disclosed in the patent just referred to, the stanchion necessarily assumes a position quite far from the desired vertical position.
Such a prior art device has the disadvantage, when the stanchion is free of engagement with the usual locking device at the bottom thereof, that the user of the device must exert force against the stanchion to keep it from swinging out of the vertical into an extreme position in which it will provide an unwanted obstacle to the movement of cartons or other lading or may bump into, or otherwise impede the movement of, the user of the device or other occupant of the freight transporting vehicle. Such swinging of the stanchion far out of its usual vertical position frequently interferes with loading or unloading activities on the part of the user of the device, is always awkward and inconvenient for the user, may result in damage to the lading, and may even result in injury to the user.
Prior art devices that tend when unrestrained to swing quite a distance out of the vertical position must, for adequate operation, include means such as horizontally disposed rollers to oppose the sidewise thrust or angular movement of the supporting carriage means that necessarily accompanies any marked swinging of the stanchion and the resulting "cocking" of the carriage means. Any tendency of these prior art stanchions to swing out of the vertical places a very considerable stress on such means that are expected to oppose swinging. In doing this, they tend to cause damage to the very means that are designed to oppose any transverse or angular movement of the stanchion.
While for all the reasons given above it is highly advantageous to avoid the extreme tendency of known freight restraining devices of the stanchion type to swing far out of the vertical attitude when the bottom end of the stanchion is unrestrained, it is at the same time desirable to permit a limited amount of swinging of the stanchion with respect to its rolling carriage assembly. For if this movement is not permitted, when horizontal displacement forces of considerable magnitude are exerted on the lower portion of the stanchion during normal use of the device, potentially damaging stress will be unavoidably placed on the carriage assembly itself or on its connection with the stanchion. With the totally rigid connection means that is characteristic of known stanchion type freight bracing devices, no limited swinging such as just discussed is permitted.
Prior to the present invention, these troublesome disadvantages of the prior art devices have been accepted as being unavoidable. The freight restraining device of this invention insures that the stanchion normally assumes a definite vertical position, and in its preferred embodiment permits at the same time a limited amount of swinging of the stanchion in response to externally applied horizontal forces of sufficient magnitude--whether accidentally applied or forces such as the user himself may from time to time desire to apply--when the bottom end of the stanchion is momentarily not restrained.